LafargeHolcim Ltd. is in talks with PPC Ltd. about combining its African assets with South Africa’s largest cement maker, a move that could challenge an existing offer from Canada’s Fairfax Financial Holdings Ltd.

The Swiss company is proposing a partial cash bid and a special dividend to shareholders, Johannesburg-based PPC said in a statement on Friday. LafargeHolcim, the world’s biggest cement maker, plans to make a firm offer during the week starting Nov. 20, after completing a due diligence process.

PPC shares jumped as much as 6.6 percent in early trade, the biggest gain in six weeks, and traded 3.2 percent higher at 6.85 rand as of 9:19 a.m. That values the company at 11 billion rand ($771 million).

PPC is already considering an offer for a stake by Toronto-based Fairfax, a proposal that’s conditional on a merger with local rival AfriSam Group Pty Ltd. PPC has given Fairfax until Nov. 22 to post its offer to shareholders, allowing other potential bidders time to do due diligence on the company.

On-Off Talks

Potential buyers have been circling PPC since on-off merger talks with AfriSam were abandoned for the most recent time in August. The 125-year-old company has new operations in African countries including Ethiopia, Zimbabwe and the Democratic Republic of Congo, and analysts see a potential construction boom on the continent in the years ahead. In South Africa, sluggish economic growth and weaker prices has made it challenging to grow the business.

No agreement with PPC has been reached and no assurance can be made that a deal will happen, Jona-based LafargeHolcim said in a separate statement on Friday. The company is the world’s largest cement maker with operations in more than 80 countries.

The PPC board “will evaluate every bona fide proposal with the potential to unlock value for shareholders,” PPC Chairman Peter Nelson said. “We believe that PPC is a solid business in its own right.”

Fairfax has offered 5.75 rand a share for 2 billion rand worth of stock. Dangote Cement Plc, Africa’s largest maker of the building material, made an indicative proposal before walking away earlier this month.

Dublin-based CRH Plc and Titan Cement Co SA of Greece are also monitoring the situation, people familiar with the matter have said.